Input device

ABSTRACT

The input device of the present invention includes: a base having a slide surface; a movable body slidable on the slide surface; a light-emitting element for emitting light; a reflective portion which is provided for the movable body and has a reflective surface for reflecting the light emitted by the light-emitting element; and a plurality of light-receiving elements for receiving the light reflected by the reflective portion.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an input device which canperform a two-dimensional or three-dimensional input operation by movinga cursor on a screen for personal computers, entertainment systems,portable terminal units and the like. More specifically, the presentinvention relates to technologies allowing for downsizing, reduction inthickness of and improvement of the operating performance of an inputdevice.

[0003] 2. Description of the Related Art

[0004] Various input devices are known for display devices such as thosefor personal computers (hereinafter, such input devices will also bereferred to as “pointing devices”). These pointing devices have varioustypes of operating systems including a resistive pressure-sensitivesystem, a distortion system, an electrostatic capacitive system, and amembrane switch. However, each of these types of pointing devices hasits own advantages and disadvantages, and no pointing device has beenfound which can simultaneously meet the requirements of excellentoperating performance, reliability (environment resistance) anddurability. Thus, a strong demand exists for a pointing device that cansimultaneously meet these requirements.

[0005] In order to satisfy such a demand, the present applicantdeveloped improved applications of optical pointing devices (JapanesePatent Applications Nos. 7-66071 and 7-161157).

[0006] The pointing device disclosed in Japanese Patent Application No.7-66071 is a highly reliable and durable pointing device which canoptically perform a two-dimensional input operation without requiringany contact for performing a detection. The pointing device is alsoexcellent in operating performance because the pointing device uses anelastic structure made of rubber.

[0007]FIG. 34 schematically illustrates the detection principles of thepointing device. The pointing device includes: an operating portion 101which is operated by the tip of a finger of an operator; a fixingportion 106; an elastic structure 102 for elastically supporting theoperating portion 101 and for connecting the operating portion 101 andthe fixing portion 106 to each other; a reflective plate 103 which isdisposed on the lower surface of the operating portion 101; a singlelight-emitting element 104; four light-receiving elements 105; and asensor portion which is fixed below the operating portion 101.

[0008] The light emitted upward from the light-emitting element 104 isreflected by the reflective plate 103 so as to be detected by thelight-receiving elements 105. As shown in FIG. 34, when the operatingportion 101 is moved to any of forward, backward, leftward and rightwarddirections, the position of the light (i.e., the location of the lightspot) received by the light-receiving elements 105 is varied, so thatthe amounts of the light received by the four light-receiving elements105, i.e., photodiodes PD1 to PD4, are also varied. The pointing deviceutilizes this principle for determining the direction and the amount ofdisplacement of the operating portion 101, that is to say, the movementdirection and the movement distance of a cursor 111 of a computer 110 orthe like, in accordance with the equations shown in FIG. 34. In otherwords, this pointing device may function as an input device for thecursor 111.

[0009] On the other hand, the pointing device described in JapanesePatent Application No. 7-161157 is a pointing device which can perform athree-dimensional input operation. The pointing device can also performa two-dimensional input operation (i.e., an operation performed in an Xdirection and a Y direction) by utilizing substantially the sameconfiguration as that of the previously described pointing device. Inperforming the three-dimensional input operation, the pointing devicecalculates the movement amount of a cursor in a Z direction inaccordance with the increase of the size of a spot of light received bythe light-receiving elements when the operating portion is pusheddownward. The size of the light spot is increased because the reflectiveplate 123 is also pushed down as the operating portion is pushed down,as shown in FIG. 35. In addition, since the increase of the size of thelight spot varies the total amount of light to be detected by the fourlight-receiving elements, the pointing device can easily calculate thecoordinate of the cursor in the Z direction.

[0010] Although the above input devices preform adequately, furtherimprovements in operating performance, reliability (environmentresistance), durability and size reduction would be desirable.

SUMMARY OF THE INVENTION

[0011] The present invention provides an input device which is easy touse, durable, reliable, provides improved operating performance and hasa reduced size.

[0012] The input device of the present invention includes: a base havinga slide surface; a movable body slidable on the slide surface; alight-emitting element for emitting light; a reflective portion which isprovided for the movable body and has a reflective surface forreflecting the light emitted by the light-emitting element; and aplurality of light-receiving elements for receiving the light reflectedby the reflective portion.

[0013] In one embodiment, the movable body is supported by an elasticstructure including an elastic body which expands/shrinks with a slidingmovement of the movable body, and the elastic structure is linked to thebase.

[0014] In another embodiment, the input device further includes a fixingportion having a guide portion for guiding the movement of the movablebody such that the movable body is slidable on the slide surface. Themovable body is supported by an elastic structure including an elasticbody which expands/shrinks with the sliding movement of the movablebody. The elastic structure is linked to the fixing portion.

[0015] In still another embodiment, the elastic body is a spiral spring.

[0016] In still another embodiment, the plurality of light-receivingelements detect the light reflected by the reflective surface onto afirst plane, and a spot diameter x of the light reflected by thereflective surface onto the first plane satisfies a relationship:d≦x≦2r+2l_(max), where d is a distance between two adjacentlight-receiving elements of the plurality of light-receiving elements; ris a diameter of a circle encircling and inscribing the plurality oflight-receiving elements; and l_(max) is a maximum movement distance ofthe movable body.

[0017] In still another embodiment, the reflective surface has areflection pattern. When the reflected light is imaged by the pluralityof light-receiving elements, the reflection pattern is turned into animaging pattern which is symmetric in any of the upward, downward,leftward and rightward directions with respect to the light-receivingsurfaces of the light-receiving elements.

[0018] In still another embodiment, the reflective surface has areflection pattern in which a reflectivity in a center of the reflectivesurface is different from a reflectivity in an outer periphery of thereflective surface.

[0019] In still another embodiment, the operating portion includes atleast one protrusion.

[0020] In still another embodiment, the operating portion includes ananti-slipping film.

[0021] In still another embodiment, at least one mark indicating anoperation direction of the operating portion is provided for the movablebody.

[0022] In still another embodiment, the mark is one of a convex one anda concave one which is formed when the movable body is molded from aresin.

[0023] In still another embodiment, the mark is one of a picture, acharacter and a pattern.

[0024] In still another embodiment, an indicator of a pointing device isprovided for the movable body.

[0025] In still another embodiment, the material of the elasticstructure is the same as that of the movable body.

[0026] In still another embodiment, the material of the elasticstructure is the same as that of the fixing portion.

[0027] In still another embodiment, the material of the elasticstructure is the same as that of the operating portion.

[0028] In still another embodiment, the movable body comes into contactwith the base in accordance with a S97517 force applied by the elasticstructure.

[0029] In still another embodiment, the movable body includes at leastthree protrusions contacting the base. The at least three protrusionsare one of spherical and hemispherical.

[0030] In still another embodiment, the base includes at least threeprotrusions contacting the movable body. The at least three protrusionsare one of spherical and hemispherical.

[0031] In still another embodiment, a flat plate is provided between themovable body and the base such that the movable body smoothly slidesrelative to the base.

[0032] In still another embodiment, a lubricant is applied between themovable body and the base such that the movable body smoothly slides onthe base.

[0033] In still another embodiment, a stopper portion for restrictingthe movement of the movable body is provided for the base.

[0034] In still another embodiment, the light-emitting element and theplurality of light-receiving elements are fixed on the base.

[0035] In still another embodiment, the movable body moves in twodimensional directions.

[0036] In still another embodiment, the input device further includes apressure-sensitive sensor for detecting a force applied to the movablebody in a Z-axis direction. The slide surface includes an X axis and a Yaxis orthogonal to the X axis, and the Z axis is orthogonal to the Xaxis and the Y axis.

[0037] In still another embodiment, the position of an object to bedisplayed on a display device is controlled in response to a detectionsignal output by the pressure-sensitive sensor.

[0038] In still another embodiment, a flat plate is disposed between themovable body and the base such that the movable body smoothly slidesrelative to the base. The pressure-sensitive sensor is disposed betweenthe flat plate and the base.

[0039] In still another embodiment, the pressure-sensitive sensor isdisposed at a contact between the movable body and the base.

[0040] In still another embodiment, the input device starts to operateas a pointing device in response to a detection signal output by thepressure-sensitive sensor.

[0041] In still another embodiment, the slide surface is planar.

[0042] In still another embodiment, the slide surface is curved.

[0043] In still another embodiment, the operating portion is concave.

[0044] In still another embodiment, the operating portion is convex.

[0045] In still another embodiment, the at least one mark is colored.

[0046] In still another embodiment, the elastic structure, the fixingportion and the movable body are molded by either one of an insertmolding technique and a two-color molding technique, and form a hermeticstructure under an upper surface of the movable body.

[0047] In still another embodiment, when the elastic structure, thefixing portion and the movable body are molded by either one of theinsert molding technique and the two-color molding technique, at least apart of the surface of the movable body is covered with the samematerial as that of the elastic structure.

[0048] In still another embodiment, the movable body includes anoperating portion to which a force is applicable by an operator.

[0049] In still another embodiment, the material of the elasticstructure is the same as that of the operating portion, and the materialof the elastic structure is the same as that of the fixing portion.

[0050] In still another embodiment, the movable body is pressed againstthe base by a force applied by the elastic structure.

[0051] In still another embodiment, the light-emitting element and theplurality of light-receiving elements are integrally molded with thebase.

[0052] In still another embodiment, the base has an upper surface and alower surface, and the pressure-sensitive sensor is placed on either oneof the upper surface and the lower surface of the base.

[0053] In still another embodiment, the pressure-sensitive sensor isdisposed on a part of the movable body which is in contact with thebase.

[0054] In still another embodiment, the start signal is output to acomputer having a power save function.

[0055] Hereinafter, the functions or the effects to be attained by thepresent invention will be described.

[0056] The input device of the present invention is an optical inputdevice of a non-contact type, and thus provides excellent durability. Inaddition, the input device provides excellent reliability (orenvironment resistance).

[0057] Moreover, the movable body (operating portion) can slidetwo-dimensionally (i.e., in the X and Y directions). Thus, as comparedwith an input device which rocks in the vertical direction, the inputdevice (i.e., the pointing device) can be downsized with a reducedthickness.

[0058] Furthermore, in the above-described configuration, the reflectivesurface moves with the movable body (i.e., the operating portion) and isdisposed so as to face the light-emitting element and thelight-receiving elements. Thus, by providing the above-describedcharacteristics for the reflection pattern thereof, a pointing deviceexhibiting linear detection characteristics over a wide range withrespect to the displacement can be easily realized. As a result, aninput device which can perform a two-dimensional input operation withimproved detection precision and enhanced operating performance can berealized.

[0059] Furthermore, in the above-described configuration, the tip of anoperator's finger does not slip on the operating portion. Thus, theoperator can easily apply force with certainty to the operating portion.As a result, the operating performance is further improved.

[0060] Moreover, if the indicators indicating the operating directionsand the like are provided for the operating portion by using coloredmarks, pictures or the like, then the operator is much less likely toperform an erroneous operation. As a result, the operating performanceis further improved.

[0061] In addition, if the elastic structure, the operating portion andthe fixing portion are formed by an insert molding technique, atwo-color molding technique or the like so as to realize a hermeticstructure under the surface of the operating portion, then a dust-proofconstruction is realized. As a result, the reliability (environmentresistance) of the input device can be improved.

[0062] Furthermore, if the elastic structure, the operating portion andthe fixing portion are positioned and configured to satisfy such apositional relationship that the operating portion comes into contactwith or is pressed against the base by the force applied by the elasticstructure when the elastic structure, the operating portion and thefixing portion are fixed onto the base, then various assembly defectssuch as backlash and lifting of the operating portion and the fixingportion can be eliminated. As a result, the assembly precision can beimproved and the costs can be reduced.

[0063] Moreover, if the movable body (operating portion) and the baseare in contact with each other via at least three spherical protrusionsor hemispherical protrusions, then the slide resistance of the operatingportion against the base can be reduced. As a result, the operatingperformance is further improved.

[0064] Furthermore, if a sheet-shaped flat plate is provided or alubricant is applied between the operating portion and the base forsmoothly sliding the operating portion, then the slide resistance can befurther reduced. As a result, the operating performance is furtherimproved.

[0065] Moreover, if a pressure-sensitive sensor for detecting the forcein the Z-axis direction which is applied onto the movable body isfurther provided, an input device which can perform a three-dimensionalinput operation, while attaining all the advantages of the input devicefor the two-dimensional input operation, is realized.

[0066] In such a case, since the pressure-sensitive sensor can preciselydetect a force applied in the Z-axis direction, it is not necessary toperform a subtle input operation in the Z direction while relying on thehuman sense of touching or subtly pushing down the operating portionwith the tip of a finger. Thus, since such an operation requires nospecial training, even a child or an old man can easily perform athree-dimensional input operation.

[0067] Thus, the invention described herein makes possible theadvantages of (1) providing an input device such as a pointing devicewhich can perform a two-dimensional and/or a three-dimensional inputoperation, can be downsized with a reduced thickness and can improve theoperating performance thereof, and (2) providing an input device whichenables even a child to easily perform the three-dimensional inputoperation without requiring any special training.

[0068] These and other advantages of the present invention will becomeapparent to those skilled in the art upon reading and understanding thefollowing detailed description with reference to the accompanyingfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0069]FIG. 1 is a cross-sectional view illustrating the input device ofthe present invention according to input device Example 1.

[0070]FIG. 2 is a plan view illustrating the input device of the presentinvention according to input device Example 1.

[0071]FIG. 3 is a cross-sectional view taken along the line A-A shown inFIG. 2.

[0072]FIG. 4 is a side view illustrating the input device of the presentinvention according to input device Example 1.

[0073]FIG. 5 is a rear view illustrating the input device of the presentinvention according to input device Example 1.

[0074]FIG. 6 is a right side view illustrating the input device of thepresent invention according to input device Example 1.

[0075]FIG. 7A is a diagram illustrating a relationship between themovement direction of an operating portion and that of a light spot inthe X-axis direction, and FIG. 7B is a diagram illustrating arelationship between the movement direction of the operating portion andthat of the light spot in the Y-axis direction in the input device ofthe present invention according to input device Example 1.

[0076]FIG. 8 is a graph illustrating a relationship between a movementdistance and a subtracted output.

[0077]FIG. 9A is a view illustrating an exemplary disposition of areflective plate 3, FIG. 9B is a diagram illustrating a normalreflection pattern, and FIG. 9C is a diagram illustrating a reflectionpattern where the reflectivity in the center region of the reflectiveplate 3 is different from the reflectivity in the peripheral region ofthe reflective plate 3.

[0078]FIG. 10 is a graph illustrating relationships between thesubtracted outputs and the movement distances for the reflectionpatterns shown in FIGS. 9B and 9C, respectively.

[0079]FIG. 11 shows a cross-sectional view and a plan view forexemplifying an optimum diameter of a light spot.

[0080]FIG. 12A is a diagram illustrating how photodiodes PD1 to PD4detect the light reflected by the reflective plate 3 on a plane 100, andFIG. 12B is a graph illustrating relationships between the movementdistances of the operating portion 1 and the subtracted outputs for thelight spots of various sizes of the reflected light.

[0081]FIG. 13 is a cross-sectional view illustrating the operatingportion of the input device according to operating portion Example 1.

[0082]FIG. 14 is a cross-sectional view illustrating the operatingportion of the input device according to operating portion Example 2.

[0083]FIG. 15 is a cross-sectional view illustrating the operatingportion of the input device according to operating portion Example 3.

[0084]FIG. 16 is a cross-sectional view illustrating the operatingportion of the input device according to operating portion Example 4.

[0085]FIG. 17 is a cross-sectional view illustrating the operatingportion of the input device according to operating portion Example 5.

[0086]FIG. 18 is a cross-sectional view illustrating the operatingportion of the input device according to operating portion Example 6.

[0087]FIGS. 19A, 19B and 19C are plan views illustrating various typesof marks contributing to the improvement of the operating performance ofthe operating portion 1.

[0088]FIGS. 20A to 20E are cross-sectional views illustrating variousconfigurations including the elastic structure 2, the operating portion1 and the fixing portion 6.

[0089]FIG. 21A is a cross-sectional view illustrating an assembly inwhich the elastic structure 2, the operating portion 1 and the fixingportion 6 have been assembled, and FIG. 21B is a cross-sectional viewillustrating the appearance of the input device after the base 4 hasbeen attached to the assembly shown in FIG. 21A.

[0090]FIG. 22A is a plan view illustrating an assembly in which theelastic structure 2, the operating portion 1 and the fixing portion 6have been assembled, and FIG. 22B is a cross-sectional view taken alongthe broken line B-B of the assembly shown in FIG. 22A.

[0091]FIG. 23A is a plan view illustrating an assembly in which theelastic structure 2, the operating portion 1 and the fixing portion 6have been assembled, and FIG. 23B is a cross-sectional view taken alongthe broken line C-C of the assembly shown in FIG. 23A.

[0092]FIG. 24 is a front cross-sectional view illustrating the inputdevice of Example 3 for improving the slidability of the operatingportion.

[0093]FIG. 25 is a front cross-sectional view illustrating the inputdevice of Example 4 for improving the slidability of the operatingportion.

[0094]FIG. 26A is a plan view illustrating an assembly in which theelastic structure 2, the operating portion 1 and the fixing portion 6have been assembled, and FIG. 26B is a cross-sectional view taken alongthe broken line D-D of the assembly shown in FIG. 26A.

[0095]FIG. 27 is a cross-sectional view illustrating the input device ofthe present invention according to input device Example 2.

[0096]FIG. 28 is a cross-sectional view illustrating the input device ofthe present invention according to input device Example 3.

[0097]FIG. 29A is a cross-sectional view illustrating the input deviceof the present invention according to input device Example 4, and

[0098]FIG. 29B is a view illustrating a spiral spring 2′.

[0099]FIGS. 30A and 30B are views illustrating the spiral spring 2′connected to the operating portion 1.

[0100]FIG. 31 is a cross-sectional view illustrating the input device ofthe present invention according to input device Example 5.

[0101]FIG. 32A is a schematic circuit diagram illustrating the detectionprinciple of a pressure-sensitive sensor, and

[0102]FIG. 32B is a graph illustrating a relationship between an appliedload and an output voltage.

[0103]FIG. 33 is a cross-sectional view illustrating the input device ofthe present invention according to input device Example 6.

[0104]FIG. 34 is an illustrative drawing explaining the detectionprinciple of a pointing device which can perform a two-dimensional inputoperation.

[0105]FIG. 35 is an illustrative drawing explaining the detectionprinciple of a pointing device which can perform a three-dimensionalinput operation.

[0106]FIG. 36 is a schematic circuit diagram illustrating the inputdevice shown in FIG. 31 or 33 with a computer having a power savefunction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0107] Hereinafter, several embodiments of the present invention will bespecifically described in the following examples with reference to theaccompanying drawings.

INPUT DEVICE EXAMPLE 1

[0108]FIGS. 1 through 12 illustrate an embodiment of the input device ofthe present invention according to input device Example 1. In inputdevice Example 1, the present invention is applied to a pointing devicewhich can perform a two-dimensional input operation.

[0109] As shown in FIGS. 1 to 6, the pointing device P includes: asquare-shaped base 4 when it is seen from above; an operating portion 1,i.e., a movable body which can slide on the base 4 in an X-axisdirection (corresponding to the lateral direction in FIG. 1) and in aY-axis direction (corresponding to the depth direction in FIG. 1) whichis orthogonal to the X-axis direction; a fixing portion 6 provided alongthe periphery of the base 4; an elastic structure 2 which elasticallysupports the operating portion 1 and connects the operating portion 1 tothe fixing portion 6; and a sensor S which is placed under a lowersurface of the operating portion 1 between the base 4 and the operatingportion 1 and is electrically and mechanically connected to the base 4.The operating portion 1 is formed in a disk shape with a concave portionformed in a center region of an upper surface thereof. The elasticstructure 2 includes elastic bodies such as blade springs.

[0110] In addition, six protrusions 10 are formed on the lower surfaceof the operating portion 1 so as to come into contact with an uppersurface of the base 4 as shown in FIG. 2. These protrusions 10 areprovided for reducing the slide resistance between the operating portion1 and the base 4 and for improving the operating performance thereof.Furthermore, a reflective plate 3 for reflecting downward the lightemitted by a light-emitting element to be described later is formed inthe center region on the lower surface of the operating portion 1.

[0111] Herein, the light reflective detector previously suggested by thepresent applicant in Japanese Patent Application No. 8-75008 is used asthe sensor S. The light reflective detector includes a singlelight-emitting element (light-emitting diode LD) and fourlight-receiving elements (hereinafter, referred to as “photodiodes” PD1to PD4) which are disposed over or under the light-emitting element LD.The base 4 is a printed wiring board (PWB) and the sensor S is solderedto the base 4 so as to be electrically connected thereto. Alternatively,the sensor S may be integrally molded and fixed with the base 4.Furthermore, the sensor S may also be molded so as to simultaneouslyfunction as the base 4. The elastic structure 2 is made of a materialsuch as rubber.

[0112] In the above-described configuration, when an operator places thetip of his finger on the concave portion of the operating portion 1 andapplies some force thereto, the operating portion 1 slides in thedirection in which the force is applied. In this case, the reflectiveplate 3 is also moved in the same direction in accordance with themovement of the operating portion 1.

[0113] The light emitted upward by the light-emitting element LD of thesensor S is reflected downward by the reflective plate 3. The reflectedlight is received by the four photodiodes PD1 to PD4 (see FIGS. 7A and7B), which photoelectrically convert the received light and then outputelectric signals corresponding to the amount of the received light.Herein, when the operating portion 1 slides, the total amount of thelight received by the four photodiodes PD1 to PD4 is varied. Accordingto the present invention, the direction and the amount of thetwo-dimensional movement of the operating portion 1 are detected bypaying particular attention to this variation.

[0114] Next, the principle of how the two-dimensional movement of theoperating portion 1 is detected will be described with reference toFIGS. 7A, 7B and 8. As described above, the light emitted by thelight-emitting element is reflected by the reflective plate 3, therebyforming a light spot over the four photodiodes PD1 through PD4.

[0115] For example, it is assumed that a light spot is located asindicated by the broken line in FIG. 7A in the initial state where theoperating portion 1 is not displaced. In such a case, when an operatormoves the operating portion 1 in the positive direction of the Xdirection with a finger, the light spot is also moved in the samepositive direction of the X direction.

[0116] Similarly, in the initial state as indicated by the broken linein FIG. 7B, when the operator moves the operating portion 1 in thepositive direction of the Y direction with a finger, the light spot isalso moved in the same positive direction of the Y direction.

[0117] Exemplary data about the movement amount of the operating portion1 in the X-axis and the Y-axis directions and subtracted outputs in sucha case are shown in FIG. 8.

[0118] The subtracted output may be calculated in the following manner.

[0119] Assuming that the photo current values of the photodiodes PD1through PD4 are represented by Isc(PD1), Isc(PD2), Isc(PD3) andIsc(PD4), respectively, the subtracted output AX in the X-axis directionis given by the following Equation (1).

AX=Isc(PD3)+Isc(PD4)−{Isc(PD1)+Isc(PD2)}  (1)

[0120] Similarly, the subtracted output AY in the Y-axis direction isgiven by the following Equation (2).

AY=Isc(PD2)+Isc(PD4)−{Isc(PD1)+Isc(PD3)}  (2)

[0121] As described above, an S-shaped curve such as that shown in FIG.8 is obtained by the pointing device of the present invention for theX-axis direction and the Y-axis direction. By synthesizing the vectorsof the output X in the X-axis direction and the output Y in the Y-axisdirection, the data about the two-dimensional direction within the rangeof 360° and the amount and the speed of an arbitrary movement areproduced. As a result, the pointing device of the present invention canperform an input operation for a display device for a computer or thelike.

[0122] However, it should be noted that in order to move the light spotin the same direction as the movement direction of the operating portion1 and to obtain the relationship shown in FIG. 8 between the movementdistance and the subtracted output, the sensor S and the reflectiveplate 3 are required to be configured so as to satisfy such a positionalrelationship that the operating portion 1 is moved in a planeperpendicular to the optical axis of the light-emitting element.

[0123] Next, an exemplary reflector as the reflective plate 3 will bedescribed in detail. According to the present invention, in order toreflect the light emitted by the light-emitting element and to form auniform imaging pattern in all directions (including upward, downward,leftward and rightward directions) on the surface of the light-receivingelements (i.e., the photodiodes PD1 to PD4) when the reflected light isimaged by the light-receiving elements, the reflection pattern of thereflective plate 3 is selected to be a circle shape or a square shapewhich is two-dimensionally symmetrical in all directions (includingupward, downward, leftward and rightward directions). The reflectionpattern is two-dimensionally symmetrical with respect to the opticalaxis of the light which has been emitted by the light-emitting elementand vertically incident on the reflective plate 3.

[0124] The reflective plate 3 is fabricated by a metal evaporationtechnique in many cases. Alternatively, the reflective plate 3 may alsobe formed as a reflective seal, a reflective coating or the like.

[0125] Moreover, in order to enlarge the region in which therelationship between the subtracted output and the movement distancelinearly varies in the curve shown in FIG. 8, the reflectivity in thecenter region of the reflective plate 3 may be different from thereflectivity in the peripheral region of the reflective plate 3.

[0126] Furthermore, the reflection pattern, formed by the reflectiveplate 3 when the reflective plate 3 reflects the light from thelight-emitting element to form a light spot on the light-receivingsurface of the photodiodes PD1 to PD4, may-have a variable reflectivitydistribution where the reflectivity varies from the center region towardthe peripheral region of the reflective plate 3.

[0127]FIG. 9A illustrates an exemplary disposition of the reflectiveplate 3, FIG. 9B illustrates a normal reflection pattern, and FIG. 9Cillustrates a reflection pattern where the reflectivity in the centerregion of the reflective plate 3 is different from the reflectivity inthe peripheral region of the reflective plate 3.

[0128]FIG. 10 illustrates the relationships between the subtractedoutput and the movement distance for the reflection patterns shown inFIGS. 9B and 9C, respectively. As shown in FIG. 10, in the case of thereflection pattern RPC shown in FIG. 9C, the region where therelationship between the subtracted output and the movement distancelinearly varies is wider than that of the reflection pattern RPB shownin FIG. 9B. Thus, even when the operating portion 1 is moved over a longdistance, the detection precision does not deteriorate. As a result, theoperating performance of the operating portion 1 is improved.

[0129] The below-described relationship is required to be satisfied bythe size of the reflective plate 3, the movement distance of theoperating portion 1 and chip of the light-receiving elements, in orderto obtain X and Y data in the two-dimensional directions. Therelationship will be described with reference to FIG. 11.

[0130] The maximum distance over which the operating portion 1 can move,i.e., the maximum distance over which the reflective plate 3, movingtogether with the operating portion 1, can move in the X direction fromthe center portion will be denoted by l_(max). The radius of the circleencircling and inscribing the four photodiodes PD1 to PD4 will bedenoted by r. The spot diameter of the light which has been reflected bythe reflective plate 3 and received by the photodiodes PD1 to PD4 on thesame plane will be denoted by x. And the gap between two adjacent onesof the photodiodes PD1 to PD4 will be denoted by d. For example, d maybe a distance between the photo-diode PD1 and the photodiode PD2. W isthe width of the photodiode.

[0131] The spot diameter x of the reflected light is determined so as tosatisfy the following relationship (3).

d≦x≦2r+2l_(max)  (3)

[0132]FIG. 12A illustrates how the photodiodes PD1 to PD4 detect thelight reflected by the reflective plate 3 on the plane 100. FIG. 12Billustrates the relationships between the movement distance of theoperating portion 1 and the subtracted output for the light spots ofvarious sizes of the reflected light. If the spot diameter of thereflected light is small (for example, if d <x), the region where therelationship between the movement distance and the subtracted outputlinearly varies becomes narrow as indicated by the curve SD. On theother hand, if the spot diameter of the reflected light is large (forexample, when x<2r+2l_(max)), there appears a flat region where nosubtracted output is obtained when the operating portion 1 is locatednear the center region as indicated by the curve LD. In order to realizeoptimum characteristics for the subtracted output as indicated by thecurve OD, the input device of the present invention is required tosatisfy the relationship (3). In order to satisfy the relationship (3),the size of the reflective plane, the light-emitting element, and/or thereflective plane, the light-emitting element and the photodiodes areadjusted.

[0133] If the operating performance of the operating portion 1 (i.e.,the pointing device) is to be improved, then it is necessary toconstruct the pointing device such that the force, applied by anoperator with the tip of a finger placed on the operating portion 1, iseasily transmitted to the operating portion 1. In other words, theoperating portion 1 is required to be configured so that the finger tipdoes not slip on the surface of the operating portion 1. Hereinafter,various examples of the operating portion 1 will be described.

OPERATING PORTION EXAMPLE 1

[0134]FIG. 13 illustrates the operating portion 1 of the input deviceaccording to operating portion example 1. The operating portion 1includes a concave portion 11 in the upper surface thereof onto whichthe tip of a finger is placed, in the same way as the operating portion1 shown in FIG. 1. In such a configuration, a force easily can beapplied with certainty onto the operating portion 1, thereby improvingthe operating performance of the operating portion 1.

OPERATING PORTION EXAMPLE 2

[0135]FIG. 14 illustrates the operating portion 1 according to operatingportion Example 2. The operating portion 1 includes: a concave portion11 in the upper surface thereof; and a protrusion 12 formed within theconcave portion 11. In such a configuration, a force easily can beapplied with certainty onto the operating portion 1, thereby improvingthe operating performance of the operating portion 1, in the same way asthe operating portion 1 shown in FIG. 13.

OPERATING PORTION EXAMPLE 3

[0136]FIG. 15 illustrates the operating portion 1 according to operatingportion Example 3. The operating portion 1 includes: a concave portion11 in the upper surface thereof; and a film 13, which is made of adifferent material from that of the operating portion 1, has anexcellent anti-slipping property or has excellent durability andenvironment resistance, and is formed over the entire upper surface ofthe operating portion 1 so as to cover the concave portion 11. In such aconfiguration, a force easily can be applied with certainty onto theoperating portion 1, thereby improving the operating performance of theoperating portion 1, in the same way as the operating portion 1 shown inFIGS. 13 or 14.

OPERATING PORTION EXAMPLE 4

[0137]FIG. 16 illustrates the operating portion 1 according to operatingportion Example 4. The operating portion 1 has a convex upper surface14. In such a configuration, a force easily can be applied withcertainty onto the operating portion 1, thereby improving the operatingperformance of the operating portion 1, in the same way as the operatingportion 1 shown in FIGS. 13, 14 or 15.

OPERATING PORTION EXAMPLE 5

[0138]FIG. 17 illustrates the operating portion 1 according to operatingportion Example 5. The operating portion 1 includes a convex uppersurface 14 and a protrusion 15 formed on the convex upper surface 14. Insuch a configuration, a force easily can be applied with certainty ontothe operating portion 1, thereby improving the operating performance ofthe operating portion 1, in the same way as the operating portion 1shown in FIGS. 13, 14, 15 or 16.

OPERATING PORTION EXAMPLE 6

[0139]FIG. 18 illustrates the operating portion 1 according to operatingportion Example 6. The operating portion 1 includes: a convex uppersurface 14; a protrusion 15 formed on the convex upper surface 14; and afilm 16, which is made of a different material from that of theoperating portion 1, has an excellent anti-slipping property or hasexcellent durability and environment resistance, and is formed over theentire upper surface 14 of the operating portion 1. In such aconfiguration, a force easily can be applied with certainty onto theoperating portion 1, thereby improving the operating performance of theoperating portion 1, in the same way as the operating portion 1 shown inFIGS. 13, 14, 15, 16 or 17.

[0140] Next, various other measures for improving the operatingperformance of the operating portion 1 to be operated by an operatorwill be described. Herein, the operating performance is improved byproviding some indicator or indicia for the operating portion 1.Hereinafter, various examples thereof will be described.

[0141] Operating portion Examples 1 to 6 of the operating portion 1 mayhave any of the marks or indicia shown in FIGS. 19A, 19B and 19C.

[0142]FIGS. 19A, 19B and 19C show various marks contributing to theimprovement of the operating performance of the operating portion 1.

[0143] In FIG. 19A, four arrow indicators 17 indicating the operatingdirections of the operating portion 1 are provided for the upper surfaceof the operating portion 1 at four positions dividing the circumferenceof the operating portion 1 into four equal parts. Specifically, theindicators 17 may be formed in a convex shape or a concave shape whenthe operating portion 1 is molded from a resin.

[0144] In FIG. 19B, four character indicators 18 (U (up), D (down), L(left) and R (right)) indicating the operating directions of theoperating portion 1 are provided for the operating portion 1. Theseindicators 18 are formed as convex or concave characters when theoperating portion 1 is molded from a resin. Alternatively, theindicators 18 may be pictures, patterns or the like, instead ofcharacters. These characters, pictures and/or patterns may be colored.

[0145] In FIG. 19C, an indicator “P.D. (pointing device)” 19 indicatingthat the operating portion 1 is a pointing device is provided for theoperating portion 1. This indicator 19 is also formed as convex orconcave characters when the operating portion 1 is molded from a resin.Alternatively, a picture or a pattern indicating that the input deviceof the present invention is a pointing device may be provided for theoperating portion 1, instead of the characters 19. The characters, thepicture and/or the pattern may be colored.

[0146] Next, various examples of the method for fabricating the inputdevice of the present invention and exemplary structures for realizingan excellent dust-proof property, reliability and environment resistancewill be described.

EXAMPLES OF FABRICATION METHOD AND STRUCTURES

[0147]FIGS. 20A to 20E illustrate various examples of the input deviceof the present invention.

[0148] In FIG. 20A, the elastic structure 2, the operating portion 1 andthe fixing portion 6 are molded by an insert molding technique or atwo-color molding technique. The elastic structure 2, the operatingportion 1 and the fixing portion 6 form a hermetic structure under theupper surface of the operating portion 1 (in the Z-axis direction). Sucha structure can inhibit or prevent dust from penetrating from over theupper surface of the operating portion 1 and deteriorating the operatingperformance of the input device. Since the upper surface of the inputdevice, from which dust is ordinarily likely to penetrate, is hermetic,the reliability (environment resistance) of the input device isimproved.

[0149] In FIG. 20B, when the elastic structure 2, the operating portion1 and the fixing portion 6 are molded by an insert molding technique ora two-color molding technique, the upper surface of the operatingportion 1 is partially or entirely covered with a film made of the samematerial as that of the elastic structure 2. Thus, the elastic structure2, the operating portion 1 and the fixing portion 6 form a hermeticstructure under the upper surface of the operating portion 1 (in theZ-axis direction).

[0150] In FIG. 20C, when the elastic structure 2, the operating portion1 and the fixing portion 6 are molded by an insert molding technique ora two-color molding technique, the operating portion 1 is made of thesame material as that of the elastic structure 2. In such an example,since the fabrication process and the resulting structure aresimplified, the costs can be reduced correspondingly. When the elasticstructure 2, the operating portion 1 and the fixing portion 6 form ahermetic structure under the upper surface of the operating portion 1(in the Z-axis direction), it is possible to inhibit or prevent dustfrom penetrating from over the upper surface of the input device.

[0151] In FIG. 20D, when the elastic structure 2, the operating portion1 and the fixing portion 6 are molded by an insert molding technique ora two-color molding technique, the fixing portion 6 is made of the samematerial as that of the elastic structure 2. In such an example, sincethe fabrication process and the resulting structure are simplified, thecosts can be reduced correspondingly. When the elastic structure 2, theoperating portion 1 and the fixing portion 6 form a hermetic structureunder the upper surface of the operating portion 1 (in the Z-axisdirection), it is possible to inhibit or prevent dust from penetratingfrom over the upper surface of the input device.

[0152] In FIG. 20E, when the elastic structure 2, the operating portion1 and the fixing portion 6 are molded by an insert molding technique ora two-color molding technique, the operating portion 1 and the fixingportion 6 are made of the same material as that of the elastic structure2. In such an example, since the fabrication process and the resultingstructure are further simplified, the costs can be further reducedcorrespondingly.

EXAMPLES CHARACTERIZED BY POSITIONAL RELATIONSHIP AND STRUCTURE OF THEELASTIC STRUCTURE, THE OPERATING PORTION AND THE FIXING PORTION

[0153]FIG. 21A illustrates an assembly including in which the elasticstructure 2, the operating portion 1 and the fixing portion 6. FIG. 21Billustrates the appearance of the input device after the base 4 has beenattached to the assembly shown in FIG. 21A.

[0154] When the assembly shown in FIG. 21A is attached to the base 4,the operating portion 1 comes into contact with the base 4 in accordancewith the amount of force applied by the elastic structure 2. When theforce applied by the elastic structure 2 is strong, the operatingportion 1 is pressed against the base 4. However, in the structure shownin FIG. 21B, the operating portion 1 can return to the initial positionthereof. In addition, if the elastic structure 2 has some rubberelasticity in the structure shown in FIG. 21B, the elastic structure 2may be operated stably.

[0155] In this example, neither backlash nor lifting is caused betweenthe operating portion 1 and the fixing portion 6. Thus, no assemblydefect is caused when the input device is constructed. As a result, theassembly precision and performance can be improved. Next, variousexamples for improving the operating performance of the operatingportion 1 and for enabling a smooth sliding of the operating portion 1,in particular, will be described.

IMPROVED SLIDABILITY EXAMPLE 1

[0156]FIG. 22A is a plan view illustrating the assembly in which theelastic structure 2, the operating portion 1 and the fixing portion 6have been formed. FIG. 22B is a cross-sectional view taken along theline B-B of the assembly shown in FIG. 22A.

[0157] At least three (six in FIGS. 22A and 22B) spherical orhemispherical protrusions 10 are formed on the lower surface of theoperating portion 1 so as to come into contact with the sliding surfacewhich is the upper surface of the base 4.

[0158] Since the operating portion 1 and the base 4 come into contactwith each other via these points, the friction resistance or the slidingresistance between the operating portion 1 and the base 4 can bereduced. As a result, the operating performance of the operating portion1 is improved.

[0159] The shape of the protrusion 10 is not limited to a sphere orhemisphere but may be any arbitrary shape so long as the protrusion 10comes into contact with the base 4 via a small number of points.

IMPROVED SLIDABILITY EXAMPLE 2

[0160]FIG. 23A is a plan view illustrating the assembly in which theelastic structure 2, the operating portion 1 and the fixing portion 6have been formed. FIG. 23B is a cross-sectional view taken along theline C-C of the assembly shown in FIG. 23A.

[0161] Though the protrusions 10 are provided on the lower surface ofthe operating portion 1 in the input device shown in FIG. 22A, theprotrusions 10 are provided on the upper surface of the base 4 in theinput device shown in FIG. 23A. At least three (six in FIGS. 23A and23B) spherical or hemispherical protrusions 10 are formed on the uppersurface of the base 4 so as to come into contact with the slide surfacewhich is the lower surface of the operating portion 1.

IMPROVED SLIDABILITY EXAMPLE 3

[0162]FIG. 24 illustrates the features of the assembly in Example 3 forimproving the slidability of the operating portion 1. In Example 3, asheet shaped flat plate 20 is formed on the upper surface of the base 4in order to smoothly sliding the operating portion 1, which is made of amaterial having a small friction resistance, between the operatingportion 1 and the base 4.

IMPROVING SLIDABILITY EXAMPLE 4

[0163]FIG. 25 is a cross-sectional view of the assembly in which theelastic structure 2, the operating portion 1 and the fixing portion 6have been formed.

[0164] In Example 4, a lubricant 21 for smoothly sliding the operatingportion 1 is applied between the operating portion 1 and the base 4.Since the slide resistance of the operating portion 1 can be furtherreduced by this example, the operating performance of the operatingportion 1 can be further improved. It is noted that the lubricant 21 maybe applied between the operating portion 1 and the base 4 in any ofimproved slidability Examples 1 to 3 for improving the slidability ofthe operating portion 1.

EXAMPLE FOR RESTRICTING MOVEMENT AMOUNT OF OPERATING PORTION AND FORPREVENTING FRACTURE OF ELASTIC STRUCTURE

[0165]FIG. 26A is a plan view illustrating the assembly in which theelastic structure 2, the operating portion 1 and the fixing portion 6have been formed. FIG. 26B is a cross-sectional view taken along theline D-D of the assembly shown in FIG. 26A.

[0166] The input device of this example includes stopper members 22 forrestricting the range through which the operating portion 1 can move.Thus, it is possible to prevent the elastic structure 2 from beingfractured by the movement of the operating portion 1. Hereinafter, aspecific example thereof will be described.

[0167] The fixing portion 6 includes sides which can come into contactwith the operating portion 1. Ring-shaped stopper members 22 aredisposed in the vicinity of the sides of the fixing portion 6. Thus, theoperating portion 1 does not come into direct contact with the fixingportion 6. When the operating portion 1 comes into contact with any ofthese stopper members 22, the movement of the operating portion 1 isstopped. After the movement of the operating portion 1 is stopped by thecontact with the stopper member 22, the spring of the elastic structure2 is not pulled any longer. Thus, it is possible to prevent the elasticstructure 2 from being fractured. It is noted that the ring shapedstoppers may be provided for the side of the operating portion 1.

INPUT DEVICE EXAMPLE 2

[0168]FIG. 27 illustrates the input device of the present inventionaccording to input device Example 2. In Example 2, the input device ofthe present invention is applied to a pointing device which can performa two-dimensional input operation.

[0169] The fixing portion 6 of the input device includes a slide portionfor enabling the operating portion 1 to slide in two-dimensionaldirections.

[0170] As shown in FIG. 27, a slide guide groove 60 is provided for thefixing portion 6. The slide portion 0 of the operating portion 1 whichis inserted into the slide guide groove 60 slides in accordance with theforce applied to the operating portion 1. The elastic structure 2 ofExample 2 has an elastic body such as a coil spring.

[0171] It is noted that the same members as those of the input deviceshown in FIG. 1 will be identified by the same reference numerals andthe description thereof will be omitted in principle. The input deviceshown in FIG. 27 can attain the same effects as those attained by theinput device shown in FIG. 1.

[0172] In the input device shown in FIG. 27, the operating portion 1thereof may be modified as described in operating portion Examples 1 to6 of the operating portion 1. Also, in the input device shown in FIG.27, the slidability of the operating portion 1 may be improved asdescribed in improved slidability Examples 1 to 4 for improving theslidability of the operating portion 1. Moreover, the input device shownin FIG. 27 may be modified as described in the example characterized bythe positional relationship and the structures of the elastic structure2, the operating portion 1 and the fixing portion 6. Furthermore, theinput device shown in FIG. 27 may be modified as described in theexample for restricting the movement amount of the operating portion 1and for preventing the fracture of the elastic structure 2. Optionally,the input device shown in FIG. 27 may be subject to a part or all of theabove-described modifications.

INPUT DEVICE EXAMPLE 3

[0173]FIG. 28 illustrates the input device of the present inventionaccording to input device Example 3. In Example 3, the input device ofthe present invention is applied to a pointing device which can performa two-dimensional input operation.

[0174] The input device of Example 3 has substantially the sameconfiguration as that of the input device of input device Example 1 or2, except that the operating portion 1 is attached to a base having acurvature so as to be able to slide thereon.

[0175] As shown in FIG. 28, when the base 4 is seen at the front, thebase 4 has an arch shape with an upwardly convex center portion. Theoperating portion 1 has an I-shape when it is seen at the front and isattached to the base 4 so as to be able to slide in any of the forward,backward, leftward and rightward directions in FIG. 28.

[0176] The same members as those of the input device Example 1 or 2 willbe identified by the same reference numerals and the detaileddescription thereof will be omitted herein.

[0177] In the input device shown in FIG. 28, the operating portion 1thereof may be modified as described in operating portion Examples 1 to6 of the operating portion 1. Also, in the input device shown in FIG.28, the slidability of the operating portion 1 may be improved asdescribed in improved slidability Examples 1 to 4 for improving theslidability of the operating portion 1. Moreover, the input device shownin FIG. 28 may be modified as described in the example characterized bythe positional relationship and the structures of the elastic structure2, the operating portion 1 and the fixing portion 6. Furthermore, theinput device shown in FIG. 28 may be modified as described in theexample for restricting the movement amount of the operating portion 1and for preventing the fracture of the elastic FIG. 28 may be subject toa part or all of the above-described modifications.

[0178] In order for the input device shown in FIG. 28 to maintainsufficient linearity in the relationship between the subtracted outputand the movement distance, the radius of curvature of the base 4 ispreferably set at a sufficiently large value as shown in FIG. 28, andthe variation in outputs caused by the variation of the reflection angleof the reflective surface is preferably smaller than the variation inoutputs caused by the movement on the reflective surface.

INPUT DEVICE EXAMPLE 4

[0179]FIG. 29A is a cross-sectional view of the input device of thepresent invention according to input device Example 4. FIG. 29Billustrates a spiral spring 2′.

[0180] The input device of input device Example 4 has the sameconfiguration as that of the input device shown in FIG. 28 except forthe elastic structure. In input device Example 4, the concentric spiralspring 2′ shown in FIG. 29B is used as an elastic body for elasticallysupporting the operating portion l.

[0181]FIGS. 30A and 30B illustrate the spiral spring 2′ connected to theoperating portion 1, showing how the spiral spring 2′ is deformed by thedisplacement of the operating portion 1 and applies a restoring force tothe operating portion 1.

[0182] The same members as those of the input device shown in FIG. 28will be identified by the same reference numerals and the detaileddescription thereof will be omitted in the input device of input deviceExample 4.

[0183] If the radius of curvature of the base 4 is small and the angularmovement direction of the light spot is reversed from the movementdirection shown in FIGS. 7A and 7B in input device Examples 3 and 4, thedetection principle disclosed in Japanese Patent Application No. 8-75008filed by the present applicant may be applied.

INPUT DEVICE EXAMPLE 5

[0184]FIGS. 31 and 32A illustrate input device Example 5 of the inputdevice of the present invention. The input device of input deviceExample 5 can perform a three-dimensional input operation.

[0185] As shown in FIG. 31, the input device of input device Example 5includes a pressure-sensitive sensor 40 for detecting a force applied inthe Z direction, in addition to the members of the input device fortwo-dimensional detection. In this example, in order to detect a forceapplied in the Z direction, the pressure-sensitive sensor 40 may bedisposed between the flat plate shaped sheet 41 constituting a slidesurface (see FIG. 33) and the base 4, may be disposed on the uppersurface or the lower surface of the base 4 or may be disposed on theupper surface of the operating portion 1.

[0186] The same members as those of the input device for thetwo-dimensional detection (e.g., the input device shown in FIG. 1) willbe identified by the same reference numerals and the detaileddescription thereof will be omitted in principle in the input device ofinput device Example 5.

[0187] The input device of input device Example 5 can inputtwo-dimensional data to a computer in the same way as the input devicefor the two-dimensional detection (e.g., the input device shown in FIG.1). Thus, the input device of input device Example 5 can point to theposition of an object which is two-dimensionally displayed on the screenby a computer. Furthermore, since the input device of input deviceExample 5 includes a pressure-sensitive sensor 40 for detecting a forceapplied in the Z direction, three-dimensional data may also be input tothe computer. Thus, the input device of input device Example 5 can pointto the position of an object which is three-dimensionally displayed onthe screen by the computer.

[0188] A sensor of a pressure-sensitive resistive type or a sensorcalled a “distortion gauge” may be used as the pressure-sensitive sensor40. In either case, the sensor utilizes physical properties for varyinga resistance value in accordance with a force applied to the sensor.

[0189] An exemplary configuration of the input device including apressure-sensitive sensor 40 of a pressure-sensitive resistive type isshown in FIG. 32A. A relationship between the load applied onto theoperating portion 1 of the input device shown in FIG. 32A and an outputvoltage resulting from the application of a voltage to the sensor isshown in FIG. 32B. As shown in FIG. 32B, the resulting output (outputvoltage) exhibits a linear characteristic with respect to a load withina prescribed range.

[0190] Since the two-dimensional input operation (in the X and Ydirections) is performed in an optical slide manner, the tensilestrength of the elastic structure 2 is set at such a value as to movethe elastic structure 2 upon the application of a small force.

[0191] In performing an input operation in the Z direction, if the forceapplied in the Z direction is stronger than the force required toperform a two-dimensional input operation, a pressure sensitive regionof the pressure-sensitive sensor 40 is used which is able to recognizethe input in the Z direction is used.

[0192] For example, if the force required for performing thetwo-dimensional input operation is in the range from about 0 to about 50gf (=about 0.49 N), then the force required for performing the inputoperation in the Z direction is set to be equal to or larger than about50 gf (=about 0.49 N). In such a case, the pressure-sensitive sensor 40is designed so as to detect a force of 50 gf (=about 0.49 N) or more.

[0193] The pressure-sensitive sensor 40 or the sensor S for detecting aforce in the Z direction may process a signal for the Z direction. Inresponse to the processed signal for the Z direction, thetwo-dimensional data input to the computer may be corrected and themovement of a cursor or the like of a display device may be controlled.By performing such a correction, the cursor can be finely moved and aninput operation satisfying the human sense can be performed.

[0194] In input device Example 5, when the cursor is movedtwo-dimensionally, the movement amount and the movement speed of thecursor may be increased in accordance with the magnitude of the forceapplied in the Z direction. For example, in the case of processingserial data of a PS/2 mouse interface, the number of dots of the X- andY-movement data, which is ordinarily composed of three bytes, may beincreased for increasing the movement amount and accelerating themovement speed. Alternatively, the interval between the transmissiontimes of the X- and Y-movement data, which is ordinarily composed ofthree bytes, may be shortened, thereby accelerating the apparentmovement speed.

[0195] In the illustrated example, the present invention is applied toan input device including an operating portion 1 which slides on aplane. Alternatively, the present invention is also applicable to aninput device including an operating portion which slides on a surfacehaving a curvature. Furthermore, the above-described examples such asthe example for improving the slidability of the operating portion 1 areapplicable to the pointing device of input device Example 5.

[0196] The input device of input device Example 5 detects an input intwo-dimensional directions and an input in the Z direction in accordancewith detection methods using different detection means. Thus, it ispossible to perform an input operation in the two-dimensional directionsand an input operation in the Z direction by distinguishing theseoperations from each other based on the human sense. As a result, byusing the input device of input device Example 5, even a child or an oldman can perform a three-dimensional input operation with ease.

INPUT DEVICE EXAMPLE 6

[0197]FIG. 33 illustrates the input device of the present inventionaccording to input device Example 6. The input device of input deviceExample 6 can perform a three-dimensional input operation.

[0198] In input device Example 6, the movement amount is decreased andthe movement speed is decelerated or the operating portion 1 is brakedin accordance with the force applied in the Z direction, as opposed toinput device Example 5. In input device Example 6, in order to detectthe force applied in the Z direction, the pressure-sensitive sensor 40may be disposed between the flat plate shaped sheet 41 constituting aslide surface and the base 4, may be disposed on the upper surface orthe lower surface of the base 4 or may be disposed at the contact regionbetween the operating portion 1 and the base 4.

[0199] Note that the operating portion 1 may be moved in an accelerativemanner in input device Examples 5 and 6.

[0200]FIG. 36 illustrates the input device shown in FIG. 31 or 33 and acomputer having a power save function. The pressure-sensitive sensor 40detects a force applied in the Z direction and outputs the detectedforce as a start signal for starting to operate the input device as apointing device to the computer having a power save function. Byutilizing such a system, the power consumption of a computer and amonitor connected to the computer can be minimized.

[0201] The input device of the present invention is an optical inputdevice of a non-contact type, and thus has excellent durability. Inaddition, the input device has excellent reliability (or environmentresistance).

[0202] Moreover, the movable body (i.e., the operating portion) canslide two-dimensionally (i.e., in the X and Y directions). Thus, ascompared with an input device rocking in the vertical direction, theinput device (i.e., the pointing device) can be downsized with a reducedthickness.

[0203] Furthermore, in the input device of the present invention, thereflective surface moves with the movable body (i.e., the operatingportion) and is disposed so as to face the light-emitting element andthe light-receiving elements. Since an appropriate pattern is selectedas the reflection pattern thereof, a pointing device exhibiting lineardetection characteristics over a wide range with respect to thedisplacement easily can be realized. As a result, an input device whichcan perform a two-dimensional input operation with improved detectionprecision and enhanced operating performance can be realized.

[0204] Furthermore, in the operating portion of the input device of thepresent invention, the tip of an operator's finger does not slip on theoperating portion. Thus, the operator can easily apply force withcertainty to the operating portion. As a result, the operatingperformance is further improved.

[0205] Moreover, in the input device of the present invention, since theindicators instructing the operating directions and the like areprovided for the operating portion by using colored marks, pictures orthe like, the operator is much less likely to perform an erroneousoperation. As a result, the operating performance is further improved.

[0206] In addition, in the input device of the present invention, sincethe elastic structure, the operating portion and the fixing portion areformed by an insert molding technique, a two-color molding technique orthe like so as to realize a hermetic structure under the surface of theoperating portion, a dustproof construction is realized. As a result,the reliability (environment resistance) of the input device can beimproved.

[0207] Furthermore, in the input device of the present invention, sincethe elastic structure, the operating portion and the fixing portion arepositioned and configured to satisfy such a positional relationship thatthe operating portion comes into contact with or is pressed against thebase by the force applied by the elastic structure when the elasticstructure, the operating portion and the fixing portion are fixed ontothe base, various assembly defects such as backlash and lifting of theoperating portion and the fixing portion can be minimized or eliminated.As a result, the assembly precision can be improved and the costs can bereduced.

[0208] Moreover, in the input device of the present invention, since themovable body (i.e., the operating portion) and the base are in contactwith each other via at least three spherical or hemisphericalprotrusions, the slide resistance of the operating portion against thebase can be reduced. As a result, the operating performance is furtherimproved.

[0209] Furthermore, in the input device of the present invention, sincea sheet-shaped flat plate is provided or a lubricant is applied betweenthe operating portion and the base for smoothly sliding the operatingportion, the slide resistance can be further reduced. As a result, theoperating performance is further improved.

[0210] Moreover, in the input device of the present invention, since apressure-sensitive sensor for detecting a force applied in the Z-axisdirection which is applied onto the movable body (i.e., the operatingportion) is further provided, it is possible to realize an input devicewhich can perform a three-dimensional input operation while attainingall the effects of the input device for the two-dimensional inputoperation. In such a case, since the pressure-sensitive sensor canprecisely detect a force applied in the Z-axis direction, it is notnecessary to perform a subtle input operation in the Z direction whilerelying on the human sense of touch or subtly pushing down the operatingportion with the tip of a finger. Thus, since such an operation requiresno special training, even a child or an old man can easily perform athree-dimensional input operation.

[0211] Various other modifications will be apparent to and can bereadily made by those skilled in the art without departing from thescope and spirit of this invention. Accordingly, it is not intended thatthe scope of the claims appended hereto be limited to the description asset forth herein, but rather that the claims be broadly construed.

What is claimed is:
 1. An input device comprising: a base having a slidesurface; a movable body slidable on the slide surface; a light-emittingelement for emitting light; a reflective portion which is provided forthe movable body and has a reflective surface for reflecting the lightemitted by the light-emitting element; a plurality of light-receivingelements for receiving the light reflected by the reflective portion;and a fixing portion provided on the base, wherein the movable body issupported by an elastic structure including an elastic body whichexpands/shrinks with a sliding of the movable body, wherein the elasticstructure is linked to the base via the fixing portion, wherein thelight-emitting element and the plurality of light-receiving elements areconnected to the base, and wherein a variation of a total amount oflight received by the plurality of light-receiving elements from thelight reflected by the reflective portion as the movable body, which hasat least a portion thereof in contact with the slide surface and whichslides on the slide surface, is detected as a direction and an amount oftwo-dimensional movement of the movable body.
 2. An input deviceaccording to claim 1 , wherein the fixing portion has a guide portionfor guiding the movement of the movable body which is slidable on theslide surface.
 3. An input device according to claim 2 , wherein theelastic body is a spiral spring.
 4. An input device according to claim 1, wherein the plurality of light-receiving elements detect the lightreflected by the reflective surface onto a first plane, and wherein aspot diameter x of the light reflected by the reflective surface ontothe first plane satisfies a relationship: d≦x≦2r+2l_(max), where d is adistance between two adjacent light receiving elements of the pluralityof light-receiving elements; r is a diameter of a circle encircling andinscribing the plurality of light-receiving elements; and l_(max) is amaximum movement distance of the movable body.
 5. An input deviceaccording to claim 1 , wherein the reflective surface has a reflectionpattern, and wherein when the reflected light is imaged by the pluralityof light-receiving elements, the reflection pattern is turned into animaging pattern which is symmetric in any of the upward, downward,leftward and rightward directions with respect to the light-receivingsurfaces of the light-receiving elements.
 6. An input device accordingto claim 1 , wherein the reflective surface has a reflection pattern inwhich a reflectivity in a center of the reflective surface is differentfrom a reflectivity in an outer periphery of the reflective surface. 7.An input device according to claim 1 , wherein the movable body includesan operating portion to which a force is applicable by an operator. 8.An input device according to claim 7 , wherein the operating portionincludes at least one protrusion.
 9. An input device according to claim8 , wherein the operating portion has an anti-slipping property.
 10. Aninput device according to claim 1 , wherein at least one mark indicatingan operation direction of the operating portion is provided for themovable body.
 11. An input device according to claim 10 , wherein themark is one of a convex one and a concave one which is formed when themovable body is molded from a resin.
 12. An input device according toclaim 10 , wherein the mark is one of a picture, a character and apattern.
 13. An input device according to claim 1 , wherein an indicatorof a pointing device is provided for the movable body.
 14. An inputdevice according to claim 1 , wherein the elastic structure and themovable body are molded by either one of an-insert molding technique anda two-color molding technique, and form a hermetic structure under anupper surface of the movable body.
 15. An input device according toclaim 14 , wherein when the elastic structure and the movable body aremolded by either one of the insert molding technique and the two colormolding technique, at least a part of the surface of the movable body iscovered with the same material as that of the elastic structure.
 16. Aninput device according to claim 1 , wherein the material of the elasticstructure is the same as that of the movable body.
 17. An input deviceaccording to claim 1 , wherein the material of the elastic structure isthe same as that of the fixing portion.
 18. An input device according toclaim 7 , wherein the material of the elastic structure is the same asthat of the operating portion.
 19. An input device according to claim 1, wherein the movable body comes into contact with the base inaccordance with a force applied by the elastic structure.
 20. An inputdevice according to claim 1 , wherein the movable body includes at leastthree protrusions contacting the base, and wherein the at least threeprotrusions are one of spherical and hemispherical.
 21. An input deviceaccording to claim 1 , wherein the base includes at least threeprotrusions contacting the movable body, and wherein the at least threeprotrusions are one of spherical and hemispherical.
 22. An input deviceaccording to claim 1 , wherein a flat plate is provided between themovable body and the base such that the movable body smoothly slides onthe base.
 23. An input device according to claim 1 , wherein a lubricantis applied between the movable body and the base such that the movablebody smoothly slides on the base.
 24. An input device according to claim1 , wherein a stopper portion for restricting the movement of themovable body is provided for the base.
 25. An input device according toclaim 1 , wherein the movable body moves in two orthogonal directions.26. An input device according to claim 1 , further comprising apressure-sensitive sensor for detecting a force applied to the movablebody in a Z-axis direction, wherein the slide surface includes an X axisand a Y axis orthogonal to the X axis, and wherein the Z axis isorthogonal to the X axis and the Y axis.
 27. An input device accordingto claim 26 , wherein the position of an object to be displayed on adisplay device is controlled in response to a detection signal output bythe pressure-sensitive sensor.
 28. An input device according to claim 27, wherein a flat plate is disposed between the movable body and the basesuch that the movable body smoothly slides relative to the base, andwherein the pressure-sensitive sensor is disposed between the flat plateand the base.
 29. An input device according to claim 26 , wherein thepressure-sensitive sensor is disposed at a contact between the movablebody and the base.
 30. An input device according to claim 26 , whereinthe input device starts to operate as a pointing device in response to adetection signal output by the pressure sensitive sensor.
 31. An inputdevice according to claim 1 , wherein the slide surface is planar. 32.An input device according to claim 1 , wherein the slide surface iscurved.
 33. An input device according to claim 7 , wherein the operatingportion is concave.
 34. An input device according to claim 7 , whereinthe operating portion is convex.
 35. An input device according to claim10 , wherein the at least one mark is colored.
 36. An input deviceaccording to claim 1 , wherein the elastic structure, the fixing portionand the movable body are molded by either one of an insert moldingtechnique and a two-color molding technique, and form a hermeticstructure under an upper surface of the movable body.
 37. An inputdevice according to claim 36 , wherein when the elastic structure, thefixing portion and the movable body are molded by either one of theinsert molding technique and the two-color molding technique, at least apart of the surface of the movable body is covered with the samematerial as that of the elastic structure.
 38. An input device accordingto claim 1 , wherein the movable body includes an operating portion towhich a force is applicable by an operator.
 39. An input deviceaccording to claim 38 , wherein the material of the elastic structure isthe same as that of the operating portion, and wherein the material ofthe elastic structure is the same as that of the fixing portion.
 40. Aninput device according to claim 1 , wherein the movable body is pressedagainst the base by a force applied by the elastic structure.
 41. Aninput device according to claim 1 , wherein the light-emitting elementand the plurality of light-receiving element are integrally molded withthe base.
 42. An input device according to claim 26 , wherein the basehas an upper surface and a lower surface, and wherein thepressure-sensitive sensor is placed on either one of the upper surfaceand the lower surface of the base.
 43. An input device according toclaim 26 , wherein the pressure-sensitive sensor is disposed on a partof the movable body which is in contact with the base.
 44. An inputdevice according to claim 30 , wherein the start signal is output to acomputer having a power save function.
 45. An input device according toclaim 1 , wherein the movable body is supported by the elastic structureat an outer periphery of the movable body.